Semiconductor package with in-package compartmental shielding and improved heat-dissipation performance

ABSTRACT

A semiconductor package includes a substrate having at least one semiconductor chip on a top surface of the substrate; a ground ring, on the top surface of the substrate, surrounding the at least one semiconductor chip; a metal-post reinforced glue wall disposed on the ground ring, surrounding the at least one semiconductor chip; a molding compound surrounding the at least one semiconductor chip, wherein a rear surface of the at least one semiconductor chip is flush with an upper surface of the molding compound; a conductive layer disposed on the molding compound and in direct contact with the rear surface of the semiconductor chip and the metal-post reinforced glue wall; a solder layer disposed on the conductive layer; and a heat sink disposed on the solder layer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.16/237,725 filed Jan. 1, 2019. The above-mentioned reference is includedin their entirety herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to the technical field of semiconductortechnology. In particular, the invention relates to a semiconductorpackage with an in-package compartmental shielding and improvedheat-dissipation performance.

2. Description of the Prior Art

Portable electronic devices, such as mobile phones, typically utilizemulti-component semiconductor modules to provide a high degree ofcircuit integration in a single molded package. The multi-componentsemiconductor module may include, for example, semiconductor chips and aplurality of electronic components mounted on a circuit board. Thecircuit board on which semiconductor chips and electronic components aremounted is packaged in a molding process to form an over-moldedsemiconductor package structure.

In order to ensure that devices such as mobile phones operate properlyin different environments to achieve the required level of performance,over-molded semiconductor packages are typically shielded fromelectromagnetic interference (EMI). The above electromagneticinterference is an adverse effect on the performance of the componentproduced in the electrical system due to electromagnetic, e.g., radiofrequency (RF) radiation and electromagnetic conduction.

As chip modules, such as system-in-package (SiP), become smaller andsmaller, the distance between components is also reduced, making thecircuits within the module more sensitive to EMI, so it is necessary todispose EMI shielding between components within the module. However, theprior art method for forming the EMI shielding in the module iscomplicated and costly. Therefore, the current challenge in thistechnology field is to provide effective EMI shielding for over-moldedsemiconductor packages without increasing package size and processcomplexity, and without significantly increasing packaging costs.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide a semiconductorpackage having an in-package compartmental shielding and improvedheat-dissipation performance.

One aspect of the invention provides a semiconductor package with anin-package compartmental shielding including a substrate having at leastone high-frequency chip and a circuit component susceptible tohigh-frequency signal interference on a top surface of the substrate, afirst ground ring, on the top surface of the substrate, surrounding thehigh-frequency chip, a first metal-post reinforced glue wall disposed onthe first ground ring, surrounding the high-frequency chip, a secondground ring surrounding the circuit component on the top surface of thesubstrate, a second metal-post reinforced glue wall disposed on thesecond ground ring surrounding the circuit component, a molding compoundcovering at least the high-frequency chip and the circuit component; anda conductive layer disposed on the molding compound and in contact withthe first metal-post reinforced glue wall and/or the second metal-postreinforced glue wall. At least one of the first metal-post reinforcedglue wall, the second metal-post reinforced glue wall, and theconductive layer comprises a magnetic or magnetizable filler so as toform an active electro-magnetic compatibility (EMC) shielding. Accordingto one embodiment, the magnetic or magnetizable filler comprises bondedneodymium iron boron (NdFeB) magnets.

Another aspect of the invention provides a semiconductor packageincluding a substrate having at least one semiconductor chip disposed ona top surface of the substrate, a ground ring surrounding thesemiconductor chip on the top surface of the substrate, a metal-postreinforced glue wall disposed on the ground ring to surround thesemiconductor chip, and a molding compound disposed only inside themetal-post reinforced glue wall and covering the semiconductor chip. Themetal-post reinforced glue wall comprises a magnetic or magnetizablefiller so as to form an active electro-magnetic compatibility (EMC)shielding. According to one embodiment, the magnetic or magnetizablefiller comprises bonded NdFeB magnets.

Still another aspect of the invention provides a semiconductor packageincluding: a substrate having at least one semiconductor chip on a topsurface of the substrate; a ground ring, on the top surface of thesubstrate, surrounding the at least one semiconductor chip; a metal-postreinforced glue wall disposed on the ground ring, surrounding the atleast one semiconductor chip; a molding compound surrounding the atleast one semiconductor chip, wherein a rear surface of the at least onesemiconductor chip is flush with an upper surface of the moldingcompound; a conductive layer disposed on the molding compound and indirect contact with the rear surface of the semiconductor chip and themetal-post reinforced glue wall; a solder layer disposed on theconductive layer; and a heat sink disposed on the solder layer.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention. In the drawings:

FIG. 1 to FIG. 5 are schematic diagrams showing a method of fabricatinga semiconductor package having an in-package compartmental shieldingaccording to an embodiment of the invention;

FIG. 6 and FIG. 7 are partial top views showing the arrangement of metalposts disposed at an overlapping region between semiconductor chips;

FIG. 8 and FIG. 9 are schematic diagrams showing a method of fabricatinga semiconductor package having an in-package compartmental shieldingaccording to another embodiment of the invention;

FIGS. 10 and 11 are schematic perspective views of a single-chip packageaccording to other embodiments of the present invention;

FIG. 12 shows that localized droplets are disposed to form a gluenetwork on the metal posts;

FIG. 13 is a schematic diagram showing the EMI shielding effect enhancedby selecting specific magnetizing direction;

FIG. 14 is a schematic cross-sectional view showing a semiconductorpackage with improved heat-dissipation performance; and

FIG. 15 is a schematic, cross-sectional view of a PCBA (PCB assembly)according to another embodiment of the invention.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present invention areclearly and completely described in the following description withreference to the accompanying drawings. It is obvious that the describedembodiments are only a part of the embodiments of the present invention,and not all embodiments. All other embodiments obtained by those skilledin the art based on the embodiments of the present invention withoutcreative efforts are within the scope of the present invention.

The present disclosure discloses a semiconductor package havingin-package shielding, such as a System-in-Package (SiP), and a method offabricating the same. SiP refers to the integration of multiplefunctional chips, including functional chips such as processors andmemories, and other components, such as passive components, into asingle package to achieve a complete function. As mentioned earlier, aselectronic systems become smaller and the density of electroniccomponents in SiP packages becomes higher and higher, electromagneticinterference (EMI) within the system is problematic, especially forhigh-frequency chip package structures, for example, high-frequencychips such as RF chips, GPS chips, and Bluetooth chips integrated intothe SiP package to form an integrated structure, which generateselectromagnetic interference between electronic components in thepackage. The present invention thus proposes a method for fabricating asemiconductor package that is simplified in process, low in cost, andeffective, and can specifically solve the problems faced by the priorart.

FIG. 1 to FIG. 5 are schematic diagrams showing a method of fabricatinga semiconductor package 1 having an in-package compartmental shieldingaccording to an embodiment of the invention. As shown in FIG. 1, asubstrate 100, such as a circuit board or a package substrate, is firstprovided. According to an embodiment of the present invention, forexample, the substrate 100 may be a two-layer substrate, for example, asubstrate having a core layer and two metal layers, but is not limitedthereto. The substrate 100 may comprise ceramic material, laminatedinsulating material, or other suitable type of material. Although notshown in FIG. 1, the substrate 100 may also include patterned metallayers or traces on its top surface 100 a and bottom surface 100 b andvias. In addition, a solder resist layer 120 (also referred to as greenpaint) may be additionally disposed on the top surface 100 a and thebottom surface 100 b of the substrate 100.

According to an embodiment of the present invention, a plurality ofsemiconductor chips 10˜12 adjacent to each other may be disposed on thetop surface 100 a of the substrate 100. For example, the semiconductorchip 10 may be a power management IC (PMIC), the semiconductor chip 11may be a radio frequency chip (RFIC), and the semiconductor chip 12 maybe a power amplifier IC (PAIC), but is not limited thereto.

Those skilled in the art will appreciate that the types of semiconductorchips 10˜12 described above are merely illustrative. In order to achievedifferent circuit functions, different semiconductor chips or componentsmay be disposed on the substrate 100, such as a processor, a flashmemory, a dynamic random access memory (DRAM), a controller or the like.In accordance with an embodiment of the present invention, at least onehigh-frequency chip or die, such as semiconductor chip 11, and at leastone circuit component or die susceptible to high-frequency signalinterference, such as semiconductor chip 12, are disposed on top surface100 a of substrate 100.

According to an embodiment of the invention, for example, thesemiconductor chips 10 and 12 may be disposed on the top surface 100 aof the substrate 100 in a wire bonding manner, and the semiconductorchip 11 may be disposed on the top surface 100 a of the substrate 100 ina flip chip bonding manner, but is not limited thereto. According to anembodiment of the invention, the semiconductor chips 10˜12 may be in theform of a bare die or a chip package.

For example, a plurality of input/output pads (I/O pads) 101 may bedisposed on the active surface of the semiconductor chip 10, andelectrically connected to the corresponding bonding pads 202 (also knownas “golden fingers”) on the top surface 100 a of the substrate 100through the bonding wires 102. According to an embodiment of theinvention, the bonding wires 102 may be gold wires or copper wires orthe like, and the surface of each bonding pad 202 is usually providedwith a solderable coating such as a nickel-gold layer or a copper-goldlayer. For example, the semiconductor chip 12 can be electricallyconnected to the top surface 100 a of the substrate 100 through thebonding wires 122.

According to an embodiment of the invention, a plurality of passivecomponents 13 may be disposed on the top surface 100 a of the substrate100. For example, the passive components 13 may comprise a capacitorcomponent, an inductor component, a resistor component, or the like, butis not limited thereto. According to an embodiment of the invention, thepassive components 13 may be disposed on the top surface 100 a of thesubstrate 100 using surface-mount technology (SMT), but is not limitedthereto. According to an embodiment of the invention, the passivecomponents 13 may be disposed on the top surface 100 a of the substrate100 between the semiconductor chips 10˜12.

According to an embodiment of the present invention, for example, groundrings 211 and 212 are disposed on the top surface 100 a of the substrate100 around the semiconductor chips 11 and 12, respectively. The groundring 211 surrounds the semiconductor chip 11 and the ground ring 212surrounds the semiconductor chip 12. According to an embodiment of theinvention, the ground rings 211 and 212 may have a continuous, annularpattern, but is not limited thereto. In some embodiments, the groundrings 211 and 212 may have a continuous, annular pattern, or the groundrings 211 and 212 may be composed of pad patterns arranged in a ringshape.

For example, the ground rings 211 and 212 may be formed of a patternedmetal layer in the substrate 100 having a solderable plating layer, forexample, a nickel-gold layer or a copper-gold layer, on the surface ofthe patterned metal layer. The ground rings 211 and 212 can be furtherelectrically connected to a ground layer (not shown) through the vias.According to an embodiment of the invention, the ground rings 211 and212 may have a partially overlapping or shared portion, for example, anoverlapping portion 213 between the semiconductor chips 11 and 12, butare not limited thereto. In some embodiments, the ground rings 211 and212 may be annular patterns that are independent of one another.

According to an embodiment of the invention, a plurality of metal posts311 are disposed on the ground ring 211, and a plurality of metal posts312 are disposed on the ground ring 212. In accordance with anembodiment of the invention, the metal posts 311, 312 may comprisecopper, silver, gold, aluminum, nickel, palladium, any combination oralloy thereof, or any suitable electrically conductive material. Forexample, the metal posts 311, 312 may be copper posts or copper-nickelalloy posts, but are not limited thereto. According to an embodiment ofthe invention, the metal posts 311 are arranged at least in one row, andthe metal posts 312 are arranged at least in one row, but are notlimited thereto. According to an embodiment of the present invention, atthe overlapping portion 213 between the semiconductor chips 11 and 12,the metal posts 311 and the metal posts 312 are arranged in a staggeredmanner, as shown in the enlarged side view on the right side of FIG. 1,in order to achieve better electromagnetic interference shieldingeffect.

According to an embodiment of the invention, the metal posts 311, 312may be formed by wire bonding, wherein one end of each of the metalposts 311, 312 is fixed on the ground rings 211, 212, and the other endis suspended (free end), as shown in FIG. 1. The metal posts 311, 312are oriented straight up, surrounding the semiconductor chips 11 and 12,respectively, like a fence. According to an embodiment of the invention,the metal posts 311, 312 have an approximately the same height h,wherein the height h is higher than the target thickness of thesubsequently formed molding compound (after grinding). Although FIG. 1illustrates metal posts 311, 312 completely surrounding semiconductorchips 11 and 12, respectively, it will be understood by those skilled inthe art that metal posts 311, 312 may surround only portions ofsemiconductor chips 11 and 12, respectively. For example, the metalposts may be disposed along only two sides or three sides of each of thesemiconductor chips 11 and 12, rather than completely surrounding. Forexample, in another embodiment, the metal posts 311, 312 are disposedonly at the overlapping portion 213 between the semiconductor chips 11and 12.

Referring to FIG. 6 and FIG. 7, which are partial top views showing themetal posts 311, 312 disposed at the overlapping portion 213 between thesemiconductor chips 11 and 12. As shown in FIG. 6, the wire diameter d₁of the metal post 311 may be equal or unequal to the wire diameter d₂ ofthe metal post 312. The pitch P₁ between the metal posts 311, the pitchP₂ between the metal posts 312, and the pitch P₃ between the metal posts311, 312 may be equal or unequal to one another. The lateral distance Sbetween the metal posts 311, 312 may be greater than or equal to zero.According to an embodiment of the present invention, for example, thelateral distance S between the metal posts 311, 312 may be in a rangefrom about one tenth to about one percent of the wavelength of theelectromagnetic wave to be shielded, but is not limited thereto. Thevalue of the lateral distance S of the metal posts 311, 312 can beselected to provide EMI shielding for a particular frequency or range offrequencies.

For example, as shown in FIG. 7, the wire diameter d₁ of the metal post311 may be equal to the wire diameter d₂ of the metal post 312, forexample, greater than or equal to 15 micrometers, and the pitch P₁between the metal posts 311 may be equal to the pitches P₃ between metalposts 311, 312, for example, approximately equal to 30 microns. It is tobe understood that the above parameters including the wire diameter d₁of the metal post 311, the wire diameter d₂ of the metal post 312, thepitch P₁ between the metal posts 311, the pitch P₂ between the metalposts 312, and the pitch P3 between the metal posts 311 and 312 can beadjusted according to the various design requirements.

In accordance with an embodiment of the invention, the stitching of themetal posts 311, 312 and the wire bonding steps of the semiconductorchips 10 and 12 may be performed simultaneously and may be completed inthe same wire bonder. In addition, according to an embodiment of thepresent invention, the wire diameters of the metal posts 311, 312 may bethe same as or different from the wire diameters of the bonding wires102 and the bonding wires 122 on the semiconductor chips 10 and 12. Forexample, the wire diameters of the metal posts 311, 312 can be greaterthan the wire diameters of the bonding wires 102 and the bonding wires122 on the semiconductor chips 10 and 12. In addition, the material ofthe metal posts 311 and 312 may be the same as or different from thematerial of the bonding wires 102 and the bonding wires 122 on thesemiconductor chips 10 and 12.

As shown in FIG. 2, after the formation of the metal posts 311, 312 iscompleted, a glue spraying or dispensing process is subsequentlyperformed, and glue 401 is sprayed or dispensed onto the metal posts311, 312 along the ground rings 211 and 212 by a nozzle 40. The glue 401is attached to the surface of the metal posts 311, 312 and filled intothe gap between the metal posts 311, 312. According to an embodiment ofthe present invention, the glue 401 may be a thermosetting resin, athermoplastic resin, an ultraviolet (UV) curing resin, or the like, butis not limited thereto. According to an embodiment of the invention, theglue 401 may be a conductive paste, such as silver or aluminum glue.According to an embodiment of the invention, the glue 401 may compriseconductive particles such as copper, silver, gold, aluminum, nickel,palladium, any combination or alloy thereof, graphene, or any suitableelectrically conductive material. According to an embodiment of theinvention, the glue 401 may further comprise filler, such as quartzparticles, diamond particles, or the like. According to an embodiment ofthe present invention, the glue 401 may further comprise a solvent or anadditive (for example, a crosslinking agent, a catalyst or a modifier),and the like.

According to one embodiment of the invention, the glue 401 may furthercomprise magnetic or magnetizable filler 402. For example, the magneticor magnetizable filler 402 may be in the form of powder or micro-sphere,but is not limited thereto. For example, the magnetic or magnetizablefiller 402 may comprise rare-earth magnetic powder that is mixed orcoated with resin. For example, the magnetic or magnetizable filler 402may comprise bonded neodymium iron boron (NdFeB) magnets. The surface ofthe bonded NdFeB magnet may be coated with epoxy resin to preventoxidation and corrosion. The bonded NdFeB magnets can be manufacturedinto multi-pole magnetization such as circumference, inner diameter, orup and down, according to the design requirements. If the product needsto withstand high temperature environment, for example, AlNiCo magnetsmay be employed.

FIG. 12 shows that localized droplets may be used to form a glue networkon the metal posts 310 a and 310 b arranged in respective tiers. Asshown in FIG. 12, the vertical localized droplets 401 d and thehorizontal localized droplet 401 c form a reverse U-shaped glue patternon the metal posts 310 a and 310 b. The reverse U-shaped glue patterncreates a mold-flow channel 403 g between the metal posts 310 a and 310b. The flowability of the glue 401 can be adjusted by controlling thetemperatures during dispensing.

Subsequently, a curing process, such as heating or UV irradiation, maybe performed such that the glue 401 adhered to the surface of the metalposts 311, 312 is cured or semi-cured. The glue 401 can strengthen themetal posts 311 and 312 so that the metal posts 311, 312 will notcollapse during the fabrication process, and can also improve theshielding effect of electromagnetic interference and heat dissipationperformance. After the curing process is completed, metal-postreinforced glue walls 411 and 412 are formed on the top surface 100 a ofthe substrate 100. The metal-post reinforced glue wall 411 includesmetal posts 311 surrounding the semiconductor chip 11 and the cured orsemi-cured glue 401. The metal-post reinforced glue wall 412 includesmetal posts 312 surrounding the semiconductor chip 12 and the cured orsemi-cured glue 401. According to an embodiment of the invention, thecuring temperature does not exceed the Curie point of the magnetic ormagnetizable filler 402 mixed in the glue 401 to prevent the magnetic ormagnetizable filler 402 from losing its permanent magnetic properties.According to another embodiment, a process for magnetizing the magneticor magnetizable filler 402 can be performed after the package level orpost-SMT system level.

According to some embodiments of the present invention, if the wirediameter d₁ of the metal post 311 and the wire diameter d₂ of the metalpost 312 are larger, for example, greater than or equal to 25micrometers, or greater than or equal to 35 micrometers, the gluespraying process may be omitted. Further, in some embodiments, it isunderstood that the steps of mounting the semiconductor chips on the topsurface of the substrate, including but not limited to, chip bonding,wire bonding, flip chip bonding or the like, as shown in FIG. 1 may beperformed after the metal posts are disposed on the ground ring as shownin FIG. 2.

As shown in FIG. 3, a molding process is then performed to form amolding compound 500 on the top surface 100 a of the substrate 100.According to an embodiment of the present invention, the moldingcompound 500 may comprise a resin material such as a thermosettingresin, a thermoplastic resin, a UV curing resin, or the like, but is notlimited thereto. According to an embodiment of the present invention,the composition of the molding compound 500 is different from thecomposition of the glue 401. For example, the composition of the glue401 may contain conductive particles, and the composition of the moldingcompound 500 basically does not contain conductive particles. However,the present invention is not limited thereto, and in some embodiments,the composition of the molding compound 500 may be the same as that ofthe glue 401, or the physical properties such as the thermal expansioncoefficient (CTE), the stress, or the elastic modulus of the moldingcompound 500 and the glue 401 can be mutually match.

According to an embodiment of the invention, the molding compound 500overflows the metal-post reinforced glue walls 411 and 412 and coversthe regions other than the metal-post reinforced glue walls 411 and 412,including the semiconductor chip 10, the bonding wires 102, 122, and thepassive components 13, which are encapsulated by the molding compound500. According to an embodiment of the present invention, the moldingcompound 500 may be formed by various suitable methods, for example,compression molding, but is not limited thereto. According to anembodiment of the invention, the molding process may further comprise acuring process, such as a thermal curing process. According to anembodiment of the invention, the curing temperature does not exceed theCurie point of the magnetic or magnetizable filler 402 mixed in the glue401 to prevent the magnetic or magnetizable filler 402 from losing itspermanent magnetic properties. The process for magnetizing the magneticor magnetizable filler 402 can be performed after the package level orpost-SMT system level. At this point, as shown in FIG. 3, the moldingcompound 500 may have a first thickness t₁ after being thermally cured,wherein the first thickness t₁ is greater than the height h of the metalposts 311, 312 and the height of the metal-post reinforced glue walls411 and 412.

As shown in FIG. 4, after the molding process is completed, a polishingor grinding process may be performed to reduce the thickness of themolding compound 500 from the first thickness t₁ to a second thicknesst₂, so that the top surfaces of the metal-post reinforced glue walls 411and 412 are exposed, and the upper end faces of the metal posts 311, 312are also exposed. At this point, the upper surface of the moldingcompound 500 is approximately flush with the top surfaces of themetal-post reinforced glue walls 411 and 412.

Finally, as shown in FIG. 5, a conductive layer 520 is formed on apredetermined region on the molding compound 500. In accordance with anembodiment of the invention, conductive layer 520 may be locateddirectly over semiconductor chips 11 and 12 and metal-post reinforcedglue walls 411 and 412. The conductive layer 520 may comprise aconductive coating, such as a conductive ink, which can include copper,silver, or other conductive metals. In another embodiment, theconductive layer 520 can comprise a layer of copper, aluminum, or othersuitable metals. According to an embodiment of the invention, theconductive layer 520 may comprise magnetic or magnetizable filler 522.For example, the magnetic or magnetizable filler 522 may be in the formof powder or micro-sphere, but is not limited thereto. For example, themagnetic or magnetizable filler 522 may comprise rare-earth magneticpowder that is mixed or coated with resin. For example, the magnetic ormagnetizable filler 522 may comprise bonded NdFeB magnets. The surfaceof the bonded NdFeB magnet may be coated with epoxy resin to preventoxidation and corrosion. The conductive layer 520 directly contacts theexposed upper end faces of the metal posts 311, 312 and forms a groundedconfiguration through the metal posts 311, 312.

It is to be understood that the coverage and pattern of the conductivelayer 520 in FIG. 5 are merely illustrative, and the present inventionshould not be limited thereto. In some embodiments, the entire surfaceon the molding compound 500, including the upper surface and the sidesurfaces, may be covered by the conductive layer 520. In someembodiments, the conductive layer 520 may cover only the semiconductorchip 11 or 12. At this point, the conductive layer 520 is in contactwith the first metal-post reinforced glue wall 411 or 412 and a portionof the upper surface of the molding compound 500.

By providing the magnetic or magnetizable filler 402 and 522 in the glue401 and the conductive layer 520, a magnetic field can be created aroundthe shielded semiconductor chips so as to form an activeelectro-magnetic compatibility (EMC) shielding. Further, the glue 401and the conductive layer 520 may be subjected to a magnetizing process.Different magnetizing directions can make different magnetic field linepatterns. By selecting specific magnetizing direction, the EMI shieldingeffect can be enhanced for specific direction, as shown in FIG. 13. Theprocess for magnetizing the magnetic or magnetizable filler 402 can beperformed after the package level or post-SMT system level.

According to another embodiment, the metal-post reinforced glue walls411 and 412 may be formed before the semiconductor chips 10˜12 aremounted on the substrate 100. The substrate 100 having thereon themetal-post reinforced glue walls 411 and 412 may be stored in thestorage area for later assembly.

Structurally, as shown in FIG. 4 and FIG. 5, an embodiment of thepresent invention discloses a semiconductor package 1 having anin-package compartmental shielding, comprising: a substrate 100 havingat least one high-frequency chip, for example, the semiconductor chip11, disposed on a top surface 100 a of the substrate 100, and a circuitcomponent susceptible to high-frequency signal interference, such as thesemiconductor chip 12. A ground ring 211 surrounds the high-frequencychip, such as the semiconductor chip 11, on the top surface 100 a of thesubstrate 100. A metal-post reinforced glue wall 411 is disposed on theground ring 211 surrounding the high-frequency chip. A ground ring 212surrounds the circuit component on the top surface 100 a of thesubstrate 100. A metal-post reinforced glue wall 412 is disposed on theground ring 212 surrounding the circuit components. A molding compound500 covers at least the high-frequency chip and the circuit component. Aconductive layer 520 is disposed on the molding compound 500 and is incontact with the metal-post reinforced glue wall 411 and/or themetal-post reinforced glue wall 412.

According to an embodiment of the invention, the metal-post reinforcedglue wall 411 includes a plurality of metal posts 311, wherein one endof each of the plurality of metal posts 311 is fixed on the ground ring211, and the other end is suspended, wherein the plurality of metalposts 311 surround the high-frequency chip (e.g., the semiconductor chip11).

According to an embodiment of the invention, the metal-post reinforcedglue wall 412 includes a plurality of metal posts 312, wherein one endof each of the plurality of metal posts 312 is fixed on the ground ring212, and the other end is suspended, wherein the plurality of metalposts 312 surround the circuit component (e.g., the semiconductor chip12).

According to an embodiment of the invention, the metal-post reinforcedglue wall 411 or the metal-post reinforced glue wall 412 furthercomprises a glue 401 attached to the surface of the metal posts 311 orthe metal posts 312. According to an embodiment of the invention, thecomposition of the molding compound 500 is different from thecomposition of the glue 401.

Please refer to FIG. 8 and FIG. 9, which are schematic diagrams showinga method for fabricating a semiconductor package with an in-packagecompartmental shielding according to another embodiment of the presentinvention, wherein like numeral numbers designate like layers,components or materials. As shown in FIG. 8, likewise, the semiconductorpackage 2 may be provided with a plurality of semiconductor chips 10˜12adjacent to each other on the top surface 100 a of the substrate 100.For example, the semiconductor chip 10 may be a power management chip(PMIC), the semiconductor chip 11 may be a radio frequency chip (RFIC),and the semiconductor chip 12 may be a power amplifier chip (PAIC), butis not limited thereto. In accordance with an embodiment of the presentinvention, at least one high-frequency chip, such as the semiconductorchip 11, and a circuit component or chip susceptible to high-frequencysignal interference, such as the semiconductor chip 12, are disposed ontop surface 100 a of substrate 100.

According to an embodiment of the present invention, for example, thesemiconductor chips 10 and 12 may be disposed on the top surface 100 aof the substrate 100 in a wire bonding manner, and the semiconductorchip 11 may be disposed on the top surface 100 a of the substrate 100 ina flip chip bonding manner, but not limited thereto. According to anembodiment of the invention, the semiconductor chips 10˜12 may be in aform of a bare chip or a chip package.

According to an embodiment of the invention, a plurality of passivecomponents 13 may be disposed on the top surface 100 a of the substrate100. For example, the passive component 13 may be a capacitor component,an inductor component, a resistor component, or the like, but is notlimited thereto. According to an embodiment of the present invention,the passive component 13 may be disposed on the top surface 100 a of thesubstrate 100 using surface-mount technology (SMT), but is not limitedthereto. According to an embodiment of the invention, the passivecomponent 13 may be disposed on the top surface 100 a of the substrate100 between the semiconductor chips 10˜12.

According to an embodiment of the present invention, for example, groundrings 210, 211, and 212 are respectively disposed on the top surface 100a of the substrate 100 around the semiconductor chips 10 to 12, whereinthe ground ring 210 surrounds the semiconductor chip 10, the ground ring211 surrounds the semiconductor chip 11, and the ground ring 212surrounds the semiconductor chip 12. According to an embodiment of theinvention, the ground rings 210˜212 may be continuous, annular patterns,but are not limited thereto. In other embodiments, the ground rings210-212 may be continuous, annular patterns, or may be composed of padpatterns arranged in a ring shape.

According to an embodiment of the invention, a plurality of metal posts310 are disposed on the ground ring 210, a plurality of metal posts 311are disposed on the ground ring 211, and a plurality of metal posts 312are disposed on the ground ring 212. In accordance with an embodiment ofthe invention, the metal posts 310˜312 may comprise copper, silver,gold, aluminum, nickel, palladium, any combination or alloy thereof, orany suitable electrically conductive material. For example, the metalposts 310˜312 may be copper posts or copper-nickel alloy posts, but arenot limited thereto. According to an embodiment of the invention, themetal posts 310˜312 are arranged in at least one row, but are notlimited thereto.

According to an embodiment of the invention, the metal posts 310˜312 maybe formed by wire bonding, wherein one end of each of the metal posts310˜312 is respectively fixed on the ground rings 210˜212, and the otherend is suspended, as shown in FIG. 1. The metal posts 310˜312 areoriented straight up, and surround the semiconductor chips 10˜12 like afence. FIG. 8 illustrates that the metal posts 310˜312 completelysurround the semiconductor chips 10˜12, respectively.

Subsequently, a glue spraying process is performed, and glue 401 issprayed on the metal posts 310˜312 along the ground rings 210˜212 byusing a nozzle 40, wherein the glue 401 is attached to the surface ofthe metal posts 310˜312 and the gap between the metal posts is filledwith the glue 401. According to an embodiment of the present invention,the glue 401 may be a thermosetting resin, a thermoplastic resin, a UVcuring resin, or the like, but is not limited thereto. According to anembodiment of the invention, the glue 401 may be a conductive paste,such as silver or aluminum glue. According to an embodiment of theinvention, the glue 401 may comprise conductive particles such ascopper, silver, gold, aluminum, nickel, palladium, any combination oralloy thereof, graphene, or any suitable electrically conductivematerial. According to an embodiment of the invention, the glue 401 mayfurther comprise a filler, such as quartz particles, diamond particles,or the like. According to an embodiment of the present invention, theglue 401 may further comprise a solvent or an additive (for example, acrosslinking agent, a catalyst or a modifier), or the like.

According to one embodiment of the invention, the glue 401 may furthercomprise magnetic or magnetizable filler 402. For example, the magneticor magnetizable filler 402 may be in the form of powder or micro-sphere,but is not limited thereto. For example, the magnetic or magnetizablefiller 402 may comprise rare-earth magnetic powder that is mixed orcoated with resin. For example, the magnetic or magnetizable filler 402may comprise bonded NdFeB magnets. The surface of the bonded NdFeBmagnet may be coated with epoxy resin to prevent oxidation andcorrosion. The bonded NdFeB magnets can be manufactured into multi-polemagnetization such as circumference, inner diameter, or up and down,according to the design requirements. If the product needs to withstandhigh temperature environment, for example, AlNiCo magnets may beemployed.

Subsequently, a curing process, such as heating or UV irradiation, maybe performed such that the glue 401 adhered to the surfaces of the metalposts 310-312 is cured or semi-cured. The glue 401 can strengthen themetal posts 310˜312 so that they do not collapse during the fabricationprocess, and can also enhance the EMI shielding effect and heatdissipation performance. After the curing process is completed,metal-post reinforced glue walls 410˜412 are formed on the top surface100 a of the substrate 100, wherein the metal-post reinforced glue wall410 includes the metal posts 310 surrounding the semiconductor chip 10and the cured or semi-cured glues. 401, the metal-post reinforced gluewall 411 includes the metal posts 311 surrounding the semiconductor chip11 and the cured or semi-cured glue 401, and the metal-post reinforcedglue wall 412 includes the metal post 312 surrounding the semiconductorchip 12 and the cured or semi-cured glue 401.

According to other embodiments of the present invention, if the wirediameters of the metal posts 310˜312 are relatively large, for example,greater than or equal to 25 micrometers, or greater than or equal to 35micrometers, the glue spraying process may be omitted. Alternatively,the glue 401 is sprayed only onto a portion of the metal posts 310˜312.

As shown in FIG. 9, a molding process is then performed to form moldingcompounds 501˜503 within the metal post-reinforced glue walls 410˜412,respectively, on the top surface 100 a of the substrate 100. Accordingto an embodiment of the present invention, the molding compounds 501˜503may comprise a resin material such as a thermosetting resin, athermoplastic resin, a UV curing resin, or the like, but are not limitedthereto. According to an embodiment of the present invention, thecomposition of the molding compounds 501˜503 is different from thecomposition of the glue 401. For example, the composition of the glue401 may include conductive particles, and the composition of the moldingcompounds 501˜503 basically does not contain conductive materials.However, the present invention is not limited thereto, and in otherembodiments, the composition of the molding compounds 501˜503 may be thesame as that of the glue 401, or the physical properties such as thermalexpansion coefficient, stress or elastic modulus of the moldingcompounds 501˜503 and the glue 401 can be mutually match.

The glue 401 may be subjected to a magnetizing process. Differentmagnetizing directions can make different magnetic field line patterns.The process for magnetizing the magnetic or magnetizable filler 402 canbe performed after the package level or post-SMT system level. Themagnetizing direction can be selected (so the magnetic field directioncan be selected) to strengthen the direction to be protected. Themagnetic field generated by the magnetic or magnetizable filler 402 canactively shield alpha particle, beta particle, and EMI on a singlepackage.

According to an embodiment of the present invention, the moldingcompounds 501˜503 do not overflow the metal-post reinforced glue walls410˜412, and thus do not cover the regions outside the metal-postreinforced glue walls 410˜412. In other words, the molding compound 501covers the semiconductor chip 10 and the bonding wires 102, the moldingcompound 502 covers the semiconductor chip 11, and the molding compound503 covers the semiconductor chip 12 and the bonding wires 122. Theareas outside the metal-post reinforced glue walls 410˜412, includingthe passive components 13, are not encapsulated by the molding compound501˜503, and may be revealed. According to an embodiment of the presentinvention, the molding compounds 501˜503 may be formed by varioussuitable methods, for example, a compression molding or a dispensingprocess, but are not limited thereto. According to an embodiment of theinvention, the molding process may further comprise a curing process,such as a thermal curing process. Since only a part of the importantcomponents are encapsulated and protected by the molding compounds501˜503, the influence of the stress of the molding compounds 501˜503 onthe substrate 100 can be reduced, thereby improving the warpage problemof the semiconductor package 2. Subsequently, the polishing process andthe conductive layer coating process as shown in FIG. 4 and FIG. 5 canbe performed, and will not be described in further detail.

According to another embodiment of the present invention, the presentdisclosure further discloses a single chip package. As shown in FIG. 10and FIG. 11, a single semiconductor chip 10, such as a processor or thelike, is provided on the top surface 100 a of the substrate 100.Connectors 108, such as ball grid array (BGA) solder balls, are providedon the bottom surface 100 b of the substrate 100. The semiconductor chip10 may be disposed on the top surface 100 a of the substrate 100 by wirebonding (such as the bonding wires 102 shown in FIG. 10), or thesemiconductor chip 10 can be disposed on the top surface 100 a of thesubstrate 100 by flip chip bonding (as shown in FIG. 11). On the topsurface 100 a of the substrate 100, likewise, a ground ring 210 isprovided to surround the semiconductor chip 10. A metal-post reinforcedglue wall 410 is disposed on the ground ring 210 to surround thesemiconductor chip 10. The metal-post reinforced glue wall 410 comprisesa plurality of metal posts 310, wherein one end of each of the pluralityof metal post 310 is fixed on the ground ring 210, the other end issuspended, and the plurality of metal posts 310 surround thesemiconductor chip 10.

The metal-post reinforced glue wall 410 further comprises a glue 401attached to the surface of the metal posts 310. According to oneembodiment of the invention, the glue 401 may further comprise magneticor magnetizable filler 402. For example, the magnetic or magnetizablefiller 402 may be in the form of powder or micro-sphere, but is notlimited thereto. For example, the magnetic or magnetizable filler 402may comprise rare-earth magnetic powder that is mixed or coated withresin. For example, the magnetic or magnetizable filler 402 may comprisebonded NdFeB magnets. The surface of the bonded NdFeB magnet may becoated with epoxy resin to prevent oxidation and corrosion. The bondedNdFeB magnets can be manufactured into multi-pole magnetization such ascircumference, inner diameter, or up and down, according to the designrequirements. If the product needs to withstand high temperatureenvironment, for example, AlNiCo magnets may be employed.

A molding compound 501 is disposed within the metal-post reinforced gluewall 410. According to an embodiment of the present invention, thecomposition of the molding compound 501 is different from thecomposition of the glue 401. For example, the composition of the glue401 may include conductive particles such as copper, silver, gold,aluminum, nickel, palladium, any combination or alloy thereof, orgraphene. The composition of the molding compound 501 basically does notcontain conductive particles. However, the present invention is notlimited thereto, and in other embodiments, the composition of themolding compound 501 may be the same as that of the glue 401, or thephysical properties such as thermal expansion coefficient, stress, orelastic modulus of the molding compound 501 and the glue 401 can bemutually match. The molding compound 501 does not overflow themetal-post reinforced glue wall 410, and thus does not cover the regionoutside the metal-post reinforced glue wall 410. The molding compound501 can be formed by various suitable methods, for example, acompression molding or a dispensing process, but is not limited thereto.Since only the semiconductor chip 10 is encapsulated and protected bythe molding compound 501, the influence of the stress of the moldingcompound 501 on the substrate 100 can be reduced, thereby improving thewarpage problem. Subsequently, the polishing process and the conductivelayer coating process as shown in FIG. 4 and FIG. 5 can be performed,and will not be described in further detail.

Compared with the prior art, the present invention has at least thefollowing advantages: (1) the disclosed method is compatible withexisting fabrication processes, and the process steps are simplified, sothe cost is relatively low; (2) the size of the disclosed semiconductorpackage or module can be minimized; (3) the arrangement of themetal-post reinforced glue walls or compartmental shielding structureson the substrate has high flexibility; (4) the disclosed method iscapable of achieving high UPH (unit per hour) mass production; and (5)by adjusting the number of rows (tiers) and metal post diameters and/orspacing, etc., the present disclosure can be flexibly applied to variousfrequency ranges in which electromagnetic radiation is to be shielded.

FIG. 14 is a schematic cross-sectional view showing a semiconductorpackage with improved heat-dissipation performance. It is understoodthat although only one semiconductor flip chip or die is shown in FIG.14, the semiconductor package may comprises multiple semiconductor chipsor dies in some embodiments as set forth in FIG. 4. The semiconductorpackage 5 shown in FIG. 14 has enhanced heat-dissipation performance,and is suited for the applications such as artificial intelligence (AI)or cryptocurrency mining.

As shown in FIG. 14, the semiconductor package 5 comprises asemiconductor chip 10 such as SoC, CPU or GPU provided on the topsurface 100 a of the substrate 100. Connectors 108, such as ball gridarray (BGA) solder balls, are provided on the bottom surface 100 b ofthe substrate 100. The semiconductor chip 10 may be mounted on the topsurface 100 a of the substrate 100 by flip chip bonding. The connectingelements 109 such as micro-bumps or copper pillars on the active surface10 a of the flipped chip 10 are aligned and bonded with the matchingpads 110 on the top surface 100 a of the substrate 100. On the topsurface 100 a of the substrate 100, likewise, a ground ring 210 isprovided to surround the semiconductor chip 10. A metal-post reinforcedglue wall 410 is disposed on the ground ring 210 to surround thesemiconductor chip 10. The metal-post reinforced glue wall 410 comprisesa plurality of metal posts 310, wherein one end of each of the pluralityof metal post 310 is fixed on the ground ring 210, the other end issuspended, and the plurality of metal posts 310 surround thesemiconductor chip 10. The metal-post reinforced glue wall 410 furthercomprises a glue 401 attached to the surface of the metal posts 310. Theglue 401 may be in the form of localized droplets so as to form a gluenetwork on the metal posts 310, as shown in FIG. 12. Optionally, anunderfill 112 may be disposed between the semiconductor chip 10 and thetop surface 100 a of the substrate 100.

A molding compound 501 is disposed on the top surface 100 a of thesubstrate 100 to surround the semiconductor chip 10 and the metal-postreinforced glue wall 410. The molding compound 501 may be a high-thermalengineering molding compound (high-thermal EMC) having higher content offiller to enhance thermal conductivity. One example of such filler maybe aluminum nitride (AlN). According to an embodiment of the presentinvention, the composition of the molding compound 501 may be differentfrom the composition of the glue 401. For example, the composition ofthe glue 401 may include conductive particles such as copper, silver,gold, aluminum, nickel, palladium, any combination or alloy thereof, orgraphene. The composition of the molding compound 501 basically does notcontain conductive particles. The physical properties such as thermalexpansion coefficient, stress, or elastic modulus of the moldingcompound 501 and the glue 401 can be mutually match. The moldingcompound 501 can be formed by various suitable methods, for example, acompression molding or a dispensing process, but is not limited thereto.After the molding compound 501 is formed, a polishing process may beperformed to remove excess molding compound 501 from the rear surface 10b of the semiconductor chip 10, thereby exposing the rear surface 10 b.At this point, the rear surface 10 b of the semiconductor chip 10 isflush with the upper surface 501 a of the molding compound 501. Theupper ends of the metal posts 310 are also exposed.

The semiconductor package 5 comprises a conductive layer (EMI shieldingmaterial) 520 on a predetermined region on the molding compound 500. Theconductive layer 520 is in direct contact with the rear surface 10 b ofthe semiconductor chip 10 and may be referred to as a “backside metal(BSM)” layer. In accordance with an embodiment of the invention, theconductive layer 520 may be located directly over semiconductor chip 10and metal-post reinforced glue walls 410. The conductive layer 520 maycomprise a conductive coating or a conductive ink, which can includegold, nickel, copper, silver, sintered silver, sputtering titaniumnickel vanadium gold alloys, or other conductive metals. In anotherembodiment, the conductive layer 520 can comprise a layer of gold,copper, aluminum, or other suitable metals. According to an embodimentof the invention, the conductive layer 520 may comprise magnetic ormagnetizable filler. For example, the magnetic or magnetizable fillermay be in the form of powder or micro-sphere, but is not limitedthereto. For example, the magnetic or magnetizable filler may compriserare-earth magnetic powder that is mixed or coated with resin. Forexample, the magnetic or magnetizable filler may comprise bonded NdFeBmagnets. The surface of the bonded NdFeB magnet may be coated with epoxyresin to prevent oxidation and corrosion. The conductive layer 520directly contacts the exposed upper end faces of the metal posts 310 andforms a grounded configuration through the metal posts 310. Thesemiconductor package 5 comprises a solder layer 530 such as solder tinlayer on the conductive layer 520. The semiconductor package 5 comprisesa heat spreader or heat sink 60 mounted directly on the solder layer530. In some embodiments, the heat sink 60 may comprises fins 610 forincreasing the heat-dissipating surface area.

FIG. 15 is a schematic, cross-sectional view of a PCBA (PCB assembly)according to another embodiment of the invention. As shown in FIG. 15,the PCBA 6 comprises a printed circuit board 600 having a top surface600 a and a bottom surface 600 b. A plurality of semiconductor packages5 a and 5 b are mounted on the top surface 600 a. The semiconductorpackages 5 a and 5 b may have identical structure as that shown in FIG.14. A single, one-piece heat sink 60 a is mounted on the semiconductorpackages 5 a and 5 b such that the single, one-piece heat sink 60 a isin direct contact with the solder layer 530 of each of the semiconductorpackages 5 a and 5 b. The semiconductor package 5 a may be disposed inclose proximity to the semiconductor package 5 b, and a gap 630 may beprovided between the semiconductor packages 5 a and 5 b directly underthe single, one-piece heat sink 60 a.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A semiconductor package, comprising: a substratehaving at least one semiconductor chip on a top surface of thesubstrate; a ground ring, on the top surface of the substrate,surrounding the at least one semiconductor chip; a metal-post reinforcedglue wall disposed on the ground ring, surrounding the at least onesemiconductor chip; a molding compound surrounding the at least onesemiconductor chip, wherein a rear surface of the at least onesemiconductor chip is flush with an upper surface of the moldingcompound; a conductive layer disposed on the molding compound and indirect contact with the rear surface of the semiconductor chip and themetal-post reinforced glue wall; a solder layer disposed on theconductive layer; and a heat sink disposed on the solder layer.
 2. Thesemiconductor package according to claim 1, wherein the metal-postreinforced glue wall comprises a plurality of metal posts, wherein oneend of each of the plurality of metal posts is fixed on the ground ring,and the other end is suspended, and the plurality of metal postssurrounds the semiconductor chip.
 3. The semiconductor package accordingto claim 2, wherein the metal-post reinforced glue wall furthercomprises a glue attached to a surface of the metal posts.
 4. Thesemiconductor package according to claim 3, wherein the glue comprises athermosetting resin, a thermoplastic resin or an ultraviolet (UV) curingresin.
 5. The semiconductor package according to claim 3, wherein theglue comprises a conductive paste.
 6. The semiconductor packageaccording to claim 3, wherein the glue comprises conductive particles.7. The semiconductor package according to claim 6, wherein theconductive particles comprise copper, silver, gold, aluminum, nickel,palladium, any combination or alloy thereof, or graphene.
 8. Thesemiconductor package according to claim 6, wherein a composition of themolding compound is different from a composition of the glue.
 9. Thesemiconductor package according to claim 2, wherein a top surface of themolding compound is flush with a top surface of the metal-postreinforced glue wall.
 10. The semiconductor package according to claim1, wherein the molding compound comprises filler to enhance thermalconductivity.
 11. The semiconductor package according to claim 10,wherein the filler comprises aluminum nitride.
 12. The semiconductorpackage according to claim 1, wherein the conductive layer comprisesgold, nickel, copper, silver, sintered silver, sputtering titaniumnickel vanadium gold alloys.
 13. The semiconductor package according toclaim 1, wherein the solder layer comprises solder tin layer.
 14. Aprinted circuit board (PCB) assembly, comprising: a printed circuitboard having a top surface; and at least one semiconductor packageaccording to claim 1 mounted on the top surface of the printed circuitboard.